Flashcards in Chem Chem Deck (45):
1
What is an element?
any material that is made up of only one type of atom
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what is a atom?
the smallest particle of an element that has all of the elements chemical properties
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What particles are atoms made of?
electrons, protons, and neutrons
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What is the atomic number?
the number of protons in the nucleus of an atom. (upper left hand corner)
atomic number = protons
protons= number of electrons
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What is the atomic mass?
the total number of protons and neutrons. atomic number- atomic mass(# below element)= neutrons .
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What is an isotope?
its when an element has equal numbers of protons but different numbers neutrons in their nuclei. (normally a radioactive form of an element)
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What is a period and what is a group on the periodic table?
what is the trend for atomic size on the periodic table?
period- a horizontal row
group- a vertical column
- going horizontal, decrease in size, going down/vertical increase in size
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What is an inner transition metal?
one of a group of chemical elements on the periodic table. They include elements 58-71 (lanthanides) and 90-103 (actinides). lanthanides are similar and actinides are radioactive.
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What is radioactivity?
the process whereby unstable atomic nuclei break down and emit radiation
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What is a alpha ray?
alpha- carry a positive electrical charge. combo of 2 protons and 2 neutrons. its large so its hard to go through things but it can damage the surface of things.
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what is a beta ray?
carry a negative charge, originate inside the nucleus. able to penetrate paper or clothing and fairly deeply into skin
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what is a gamma ray?
carry no charge. are the high frequency electromagnetic radiation emitted by radioactive elements. can penetrate most materials.
13
What is a nucleon?
What is the strong nuclear force?
- a collective name for protons and neutrons.
-a force that holds quarks together in elementary particles. it is the strongest force known in nature.
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How do you find alpha decay?
you use 4/2 He.
example:
226/88 Ra becomes=
222/86 Rn... you subtract 4 on the top and subtract 2 on the bottom
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How do you find beta decay?
you use o/-1 e
example:
3/1H becomes
3/2 He... the top stays the same and the bottom you add one
16
What is nuclear fission?
either a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller parts. The fission process often produces free neutrons and gamma photons, and releases a very large amount of energy.
-used for atomic bombs
17
What does E=mc2 mean?
E= energy that any mass has at rest
m= mass
c= speed of light
c2= proportionally constant of energy and mass
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Where does nuclear fusion occur?
extremely high temps found in the sun and other stars.
-used for hydrogen bombs
-more powerful
-2 light nuclei combine to form a heavy nucleus
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what is matter?
physical substance that occupies space and possesses rest mass
20
what is a pure substance?
a substance that consists of only a single element or a single compound (element and compound)
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What is a element?
any material that is made up of only one type of atom--pure
examples: gold, sulfur, nitrogen
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what is a compound?
a material in which atoms of different elements are bonded to one another.
examples- salt, carbon dioxide, ammonia
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what is a homogenous mixture?
a mixture in which the components are so finely mixed that the composition is the same through out--impure
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what is a heterogenous mixture?
a mixture in which the various components can be seen as individual substances--impure
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what is a solution?
a homogenous mixture in which all components are in the same phase- examples- air, salt water, white gold
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what is a suspension?
a homogenous mixture in which the various components are in different phases- examples- milk, blood, fog
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whats the difference between a solution and a suspension?
particle sizes. solution is a mixture of ions or molecules and it looks transparent. suspension has bigger particle sizes and it looks cloudy
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How do you find the concentration of a solution?
amount of solute/ around of solution
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How do you find molarity?
# of moles of solute/ liters of solution
30
Why won't a power plant- nuclear reaction to explode?
-The U235 are highly diluted with U238
-Two separate water systems are used so that no radioactivity reaches the turbine or the outside environment
31
Whats an ionic bond?
-when one atom is + charged ( the one that gives) and the other is - charged (the one that receives) its the opposite charge that attracts and holds them together
32
what is a covalent bond?
- a chemical bond that involves the sharing of electron paris between atoms. holds together by a mutual attraction
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what is a polar covalent bond?
- a pair of electons is unequally shared between two atoms.
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what is a metallic bond?
- chemical bond that holds the atoms of a metal together.
35
How do you form ionic compounds?
look at the columns on the table: +1, +2..... +3, x, -3, -2, -1, x. then you add it up. example:
Na + Cl = Na (+1) + Cl (-1) = NaCl
everything has to come out to zero
36
How does the polarity of a molecule affect how molecules are attracted to each other?
the positive and negative ends of polar molecules attract each other.
37
What is a dipole?
positive electric charge is separated from a concentration of negative charge
38
Whats a ion-dipole?
attraction between an ion and and the dipole of a polar molecule
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whats a dipole-dipole?
an attraction between two polar molecules
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whats a dipole-induced dipole?
attraction between a permanent dipole and the induced dipole
41
what is a induced dipole-induced dipole?
a temporary dipole induces a nonpolar molecule to a induced dipole
42
Whats solubility?
Why do substances have different solubility?
-the ability of a solute to dissolve in a given solvent
- attractions between solute and solvent particles, point of saturation and temp
43
Why does soap work?
what are the two parts in the soap molecule?
- it has both polar and non polar properties
-a long non polar tail of carbon and hydrogen atoms and a head containing at least one ionic bond
44
soap process
attracts non polar grime via induced dipole-induced dipole attraction. W/ the non polar tails facing inward toward the grime, the polar heads are all directed outward, where they are attracted to water molecules by strong ion-dipole attractions. if water is going, combo goes down drain.
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